The Sustainability related opportunities and challenges with various transformer insulation fluids and business case on re-refining

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The Sustainability related opportunities and challenges with various transformer insulation fluids and business case on

re-refining

Authors: Abdulbasit Abdulaziz Ali ; Ibrahim Gharib Ali Jalal Examinater: Prof. Lars J Petterson

E-mail addresses: abdaa@kth.se; ibrahimg@kth.se

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Abstract

Transformers are electrical devices used in practice to increase or decrease voltages.

Transformers are of various sizes and used mainly in power distribution. To provide cooling and insulation, transformer oils are used together with cellulose that acts as a solid insulation.

The most common type of transformer oil is mineral oil and is a product derived from the refining of crude oil. Its low cost and good compatibility with cellulose are two factors that have led to its predominant position as the common transformer oil.

There are also synthetic ester based transformer oils, and following an increased interest in environmentally friendly products, transformer oils made from natural esters such as sunflower, soybean and rapeseed.

Mineral oil is not biodegradable and is deemed as hazardous waste. The ester based oils are biodegradable and promoted as a more environmentally friendly alternative to mineral oil.

In this thesis, the possibility of re-refining used mineral transformer oil is assessed from a financial perspective in the form of a business case and an LCA study has been done to compare the environmental impacts between ester based transformer oils and mineral based transformer oil.

The results from the LCA study showed that from a cradle-to-gate perspective, mineral oil has a lower environmental impact than ester-based transformer oils. The re-refining of used mineral transformer oil further reduces the environmental

impact. The results from the business case showed that a small scale re-refining facility is financially feasible but highly dependent on the supply and demand of used transformer oil.

It is recommended to pursue further studies before making any decision. There is lack of data regarding the re-refining market in Eastern Europe and the accuracy of the LCA study can be further improved by having emissions data from re-refining used mineral transformer oil.

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Sammanfattning

Transformatorer är elektriska komponenter som tillämpas vid spänningsregleringar.

Dessa transformatorer har olika storlekar och används i eldistribution.

Transformatorolja tillsammans med cellulosa används som elektrisk isolering och kylning av transformatorer.

Den vanligaste typen av transformatorolja är mineralolja och är en produkt som erhålls vid raffinering av råolja. Dess låga kostnad och goda kompatibilitet med cellulosa är två faktorer som har lett till dess dominerande ställning. Det finns också syntetisk esterbaserad transformatorolja och efter ett ökat intresse för miljövänliga produkter så tillverkas även transformatoroljor av naturliga estrar så som solros, soja och raps.

Mineralolja är inte nedbrytbar och anses vara farligt avfall. De esterbaserade oljorna är nedbrytbara och anses vara ett mer miljövänligt alternativ till mineralolja.

I denna rapport utvärderades möjligheten till att återraffinera använd mineralolja ur ett ekonomiskt perspektiv i form av en affärsplan och en LCA-studie där

esterbaserad olja och mineralolja har jämförts ur ett miljöperspektiv.

Resultaten från LCA-studien visade att mineralolja från ett ”cradle-to-gate”

perspektiv har en lägre miljöpåverkan än esterbaserade transformatoroljor.

Återraffinering av använd mineralolja minskar dess miljöpåverkan ytterligare.

Resultatet från affärsplanen visade att en småskalig återraffineringsanläggning är ekonomiskt hållbar men samtidigt väldigt beroende av utbud respektive

efterfrågan på använd mineralolja.

Det rekommenderas att göra en djupare analys innan man fattar ett beslut. Det finns brist på information med avseende på återraffineringsmarknaden i Östeuropa.

Noggrannheten på LCA-studien kan förbättras ytterligare genom att emissionsdata från en återraffineringsanläggning är tillgänglig.

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Nomenclature

LCA – Life Cycle Assessment

DBPC – Ditertiarybutyl para-cresol DBP – Ditertiarybutyl phenol PCB – Polychlorinated biphenyl VOC – Volatile Organic Ester

IEC – International Electrotechnical Comission ASTM – American Society for Testing and Materials DDF – Dielectric Dissipation Factor

IFT – Interfacial tension

HPLC – High Performance Liquid Chromatography DP – Degree of Polymerisation

AC – Alternating Current DGA – Dissolved Gas Analysis

CSIRO - Commonwealth Scientific and Industrial Research Organisation EIA – Environmental Impact Assessment

ERA – Ecological Risk Assessment LCI – Life Cycle Inventory

LCIA – Life Cycle Impact Assessment

EC-JRC – European Commission Joint Research Centre ILCD – International reference Life Cycle Data system BEES – Building for Environmental and Economic Stability NIST – National Institute of Standards and Technology EWC – European Waste Code

UNECE -United Nations Economic Commission for Europe

ADR – Agreement concerning the international carriage of Dangerous Goods CAPEX – Capital Expenditure

OPEX – Operating Expenditure UTO – Used Transformer Oil

MBtu – Million British thermal unit MJ – Megajoules

SIGAUS - Sistema Integral de Gestión de Aceites Usados

SOGILUB – Socidade de Gestão Integrada de Óleos Lubrificantes Usados BVA – Bundesverband Altöl

ENDIALE – Alternative Waste Management for Lubricating Oils

CONOU – Consorzio Nazionale per la gestione, raccolta e trattamento degli oli minerali usato

ORA – Oil Recycling Association NPV - Net Present Value

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Transformers are essentially electrical devices used to either increase or decrease voltages. The main purpose of this is to reduce transmission losses by reducing the current for a given electrical power. There are several different types of transformers such as power transformers and distribution transformers. The transformers,

besides their function, are divided further into two categories depending on what type of insulation they use. These are oil immersed and dry-type transformers. In the oil- immersed transformers, transformer oils are used to provide both insulation and cooling. Transformer oils are also used as impregnators of cellulose in transformers.

The cellulose, which is wrapped around the coils of a transformer, can get oxidised when exposed to air, lowering its dielectric strength. The impregnation of the cellulose with oil drives away the air and other gases to prevent oxidation. The volumes of oil in the transformers vary from a few litres in distribution transformers to several thousand litres for power transformers [1].

In many applications, they are used to ensure both the electrical insulation and the heat transfer of a component or a system, as in the case of transformers. The transformer oil is also used because of its capability to extinguish electrical arcs within the transformer [1] [2].

The usage of oil as insulation material began in the end of the 19th century with the use of petrol oil and progressed later to mineral oil and other types of insulating oils.

The main disadvantage of mineral oil is its weak resistance to fire. This lead to the development of PCB in the 1930’s and was used frequently due to its non-flammable nature. In the 1970’s, PCB was banned because of its toxicity and persistence in the environment. As a reaction to this, new synthetic oils were developed with low flammability as silicone oil and synthetic esters. Following an increased interest in environmentally friendly products, insulating oil made from natural esters has been developed and becoming an increasingly common sight as an insulating oil in

transformers [1].

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Project objective

This thesis aims at assessing the possibility of re-refining used mineral oil for use in transformers. The assessment will be done in the form of an LCA where different alternatives to mineral-based transformer oil will be studied and a business case where the feasibility of re-refining used mineral oil at Nynas will be investigated. The thesis will focus on the following tasks:

1. Evaluating existing scrapping procedures and explore possible new venues for used mineral-based transformer oil

2. The environmental impact of re-refining used mineral-based transformer oil 3. Comparison between ester based transformer oil and mineral based transformer oil.

4. Market analysis of the re-refining market.

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Transformer oils Mineral oil

Mineral oil is the most frequently used insulating fluid in electrical equipment. It is used for its good dielectric ability, heat transfer properties, its compatibility with cellulose insulators and most importantly because of its low cost. Power transformers require between 40.000 to 80.000 litres of oil which makes cost the most important factor when considering transformer oils and makes mineral oil the most common insulator fluid [1]. The structure of the hydrocarbons determines the composition and the quality of the oil:

· Paraffinic structure: Saturated hydrocarbons that are linear in structure and the general formula for these structures are 2 +2. Hydrocarbons with this kind of structure, also known as waxes, have bad flow properties at low temperatures and is known to have lower thermal stability than naphthenic and aromatic molecules [2].

· Naphthenic structure: Molecules in this group have saturated cyclical structures with the general formula 2 . The cycloalkanes have better properties than paraffins at low temperatures [2].

· Aromatic structure: These molecules are unsaturated hydrocarbons with the general formula 2 −6. They are different from naphthenic and paraffinic molecules but play an important part in the properties of a mineral oil. There are two forms: the monoaromatics and the polyaromatics which are

considered carcinogenic. The aromatic components allow the oil to have good resistance against oxidation and good absorption capacity of gases [2].

Mineral oils also contain a small percentage of hydrocarbons with heteroatoms in their structure such as nitrogen, sulphur, and oxygen [2]. Mineral transformer oils consist of mainly of naphthenic oils and not paraffinic. This is because of the better solvency power of the naphthenic structures and the previously mentioned low

temperature properties. One of the main advantages of mineral transformer oil is that they have a low viscosity compared to other transformer oils which allows for good heat transfer and good impregnation of cellulose [1].

Mineral transformer oils are either uninhibited or inhibited. The purpose of the inhibitor is to prevent the oxidation of the oil and the solid insulation. The uninhibited oils contain natural compounds which destroys peroxides that are formed during oxidation. For inhibited oils, this is achieved by adding synthetic additives such as DBPC and DBP [3].

Mineral oils also have a low pour point. The pour point is the lowest temperature at which oil will flow. The main disadvantage of mineral transformer oil is its low flammability. The flash point, which is the ignition temperature when exposed to an ignition source, is at 140 - 150 C° which is relatively low in comparison to other transformer oils [4] [5].

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10 Refining

The raw material for mineral oil is crude oil and it is refined to mineral oil through several processes. The type of crude oil is important for the possible amount of mineral oil produced. The crude oil, depending on where it is extracted from, has both different densities and compositions of naphthenes, paraffins and aromatics.

The naphthenic crude oil is heavy and is usually rich in bitumen and heavy distillate.

In oil refining, the first step is generally distillation [2].

There are mainly two types of distillation used, atmospheric and vacuum.

Atmospheric distillation involves heating, vaporisation, fractionation, condensation and cooling. In the process, the crude oil is separated into distillates with different boiling point ranges by fractionation. For light crudes, only normal pressures are required which is why atmospheric distillation is used. The crude oil is heated to about 300-400 °C and fed to a vertical distillation column where most of the feed is vaporised and separated in to its various fractions by condensing on fractionation trays. Each of the trays corresponds into different condensation temperatures.

Vacuum distillation is done by inducing a vacuum in the distillation unit, lowering the boiling point of the crude oil (hydrocarbons) allowing fractionation of the heavier crude. The fractionated products from the distillation correspond to a different type of petroleum product. Mineral transformer oil is in the subcategory “base oils” which is a part of a larger category called lubricating oils and about 1 to 2% of a barrel of crude oil is suitable for refining into base oil [6]. The additional processes needed to derive mineral transformer oil depend on the type of refinery and the supply of crude oil [7] [2].

A common technique that is used currently to produce mineral oil is hydrogenation.

Hydrogenation is based on the chemical reaction between molecular hydrogen and other molecules in the presence of a catalyst. Undesirable molecules from the crude oil refining process can be converted into more desirable ones. Typical reactor conditions vary but are typically 30 to 40 bar and 320-380°C. The catalyst itself can be described as a porous heterogeneous type of catalyst with catalytically active metals that has a large surface area. Nickel, palladium, platinum are common catalysts for this type of reaction [8].

Synthetic ester

Synthetic ester oils are becoming increasingly common as insulating fluids for transformers. Ester oils for transformers are known as pentaerythritol esters. They were developed because the ban of PCB for the impregnation of the cellulose

insulation. Pentaerythritol esters are also known as tetraesters because they are made from tetraalcohols and a mixture of monocarboxylic acids. The reaction scheme for the esterification is described below:

Pentaerythritol(tetraester) + monocarboxylic acids ⇒ pentaerythritol ester (tetraester) + water

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11 The main benefit of this type of insulating oil compared to other alternatives is the high concentration of water it can contain. Humidity is a significant problem in transformers because the cellulose paper in a humid environment absorbs the water, decreasing its dielectric strength. Ester oils can absorb up 20 or 30 times more moisture than mineral oil. This makes humidity less of a factor to consider but the high absorption also dries the paper which makes a trade-off between the increased longevity of the transformer and the increased care of handling due to higher

solubility [9].

The other advantages synthetic ester oil has over mineral oil is that it has better fire resistance with a fire point higher than 300°C and that it is biodegradable [10].

There are however disadvantages with synthetic ester oils. The main point is its viscosity. The viscosity is high in comparison to other oils and becomes significant at low temperatures. Tetraesters such as pentaerythritol esters are generally used for

“fire resistant” distribution transformers because of their high fire point. The use of synthetic esters in distribution transformers has become more common but in power transformers because of its high cost, they are 4-8 times more expensive than mineral oil [10].

Natural ester

Vegetable oils or natural esters are naturally synthesized from living organisms and usually from soy, sunflower and rapeseed. Natural esters are synthesized from a tri- alcohol such as glycerol with three monocarboxylic acids, otherwise known as fatty acids. The esterification reaction is described as following:

Glycerol + 3 monocarboxylic acids -→triglycerides (natural esters) + water The most significant advantage natural esters possess is that it has good

biodegradability potential making it a “green” alternative to other insulating oils. Its biodegradable capabilities also make it more sensitive to oxidation, limiting its use and utilizing other non-green products such as antioxidants to compensate for the high sensitivity.

Similar to synthetic esters, natural esters have both a high fire point and high water solubility. This type of oil, just like its synthetic equivalent, has higher viscosity than mineral oil which limits its heat transferring capabilities and high pour point further limiting its use to regions where the climate is not cold. In the case of natural esters, the type of fatty acids used in the esterification process affect its properties

significantly. Oils with a high percentage of unsaturated fatty acids have lower viscosities and lower pour points and vice versa for saturated acids [1] [10].

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12 Refining of natural esters

Natural esters are refined in a different way from mineral-based transformer oil. The base material is not crude oil but oil seeds and the manufacturing of the oil is done in several stages and techniques. The initial step is to dehull or to “crack” all of the seed for the extraction of the crude vegetable oil, there are two primary techniques. For sunflower and rapeseed seeds, batch processing is used where the oil is extracted by applying hydraulic pressure. For harder seeds as soybean, the crude oil is obtained by crushing the seeds and extracted with a solvent, primarily hexane. A degumming step follows the crude oil extraction step. In the degumming step, materials other than oil such as seed particles and impurities are removed from the crude vegetable oil. After the degumming step, the oil is first neutralised if it is refined chemically or winterised right after the degumming if it is refined through pressing. Alkali neutralisation reduces the content of fatty acids and carbohydrates from the oil.

Winterisation is done to remove waxes from the oil through crystallisation and filtering of the crystallised waxes. Lastly, the oil is deodorised whereby VOCs are removed through steam. The oil produced after all of these processes is known as RBD oil and in order to make it into transformer oil, additives are added to enhance the oxidation stability and reduce the pour point [4] [11].

Figure 1 - Description of natural ester refining [11]

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Requirements (IEC and ASTM)

In order for transformer oils to be used as insulation in transformers, they must fulfil certain requirements. These requirements are different depending on the type of insulating oil. The standards used internationally are set by two organisations called IEC and ASTM. For new mineral transformer oil, the most important regulations are IEC 60296 and ASTM D3487. They specify the necessary viscosity, pour point, flash point and other requirements of the oil. These requirements also involve tests to evaluate the condition of the oil after it has been in a transformer. For new and unused natural ester based transformer oil, IEC 62770 is to be followed and for synthetic esters IEC 61099. IEC and ASTM outline testing methods and requirements for every stage of a product’s lifetime.

Solid insulation

The solid insulation in transformers is largely made of cellulose in the form of kraft paper, also known as electrotechnical paper, and pressboard. The paper provides important functions to the transformer in the form of electrical insulation,

mechanical stability among others. The pressboard is used mostly in high-voltage equipment such as power transformers. The main reason for the use of cellulose is because of its good electrical properties, availability, and its interaction with mineral oil. Cellulose impregnated with mineral oil provides more electrical insulation than just the individual components. The dielectric strength of pressboard impregnated with oil is approximately three to four times greater than the dielectric strength of just oil [2].

Because of the accumulation of moisture inside the transformer, drying is an important process. Moisture in insulating material causes reduction in dielectric strength, acceleration of cellulose aging and an increase in dielectric losses. The aging of the solid insulation will affect the strength of the transformer. Water affects

cellulose through hydrolysis. Hydrolysis is the breakdown of chemical bonds with the aid of water and although the cellulose is dried in the transformer, moisture can be picked up from the surrounding air through the oil and water is also formed from the degradation of cellulose and through the degradation of oil [2].

The DP is defined as the number of monomeric units per each individual molecule. It is the most useful parameter of evaluating the aging progress of cellulose. The DP value of new cellulose is in the range of 1200-1400. When the DP value reaches 200, it is considered not satisfactory for use in transformers and other electrical equipment [2] [12].

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Analytical methods for transformer oil aging

To assess the health state of the transformer oil, a number of different physical, electrical and chemical methods are used. Continuous inspection of the state of the transformer oil is critical for it to last for long time.

Colour

The colour and appearance of the oil can serve as indicators for oil degradation and contaminants. The oil is compared to a spectrum of colours and generally oil that is contaminated can have a cloudy appearance while new transformer oil is clear [2].

Dielectric dissipation factor

The DDF measures the leakage current through the oil which assists in analysing the deterioration of the transformer within the oil. In practice, it can reveal the presence of moisture resin, varnish and other contaminants. An increase in DDF means loss of dielectric strength in the oil [13].

Interfacial tension

The IFT measures the tension at the interface of two immiscible fluids. It provides a means of detecting soluble polar contaminants and oil degradation. The IFT between oil and water varies during the initial stages of oil aging but stabilises when the deterioration is still moderate [14].

Acidity

Acids form in the oil due to the acidic products that form during oxidation. These acids cause damage as corrosion in the metallic parts of the transformer and degrade the solid insulation. Acidity tests are expressed in the unit KOH/g oil, the amount needed to neutralise the acid. An increase in acidity indicates an increased rate of deterioration, leading to the formation of sludge inside the transformer. This makes the acidity test useful in determining what should be done with the used oil [13] [14].

Furfural analysis

Furfural analysis is used when evaluating the aging condition of the insulation paper.

Furfural (or 2-FAL) is a furan compound that is generated during the cellulose degradation and is released into the oil. It is analysed by using HPLC. It is said to be an indirect correlation between the DP and furfural values. Although it is not

currently possible to establish a precise link between the furfural content and the DP- value, information about the thermal behaviour of the solid insulation can be

obtained by analysing the trend of DP and furfural values [15].

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15 Breakdown voltage

The dielectric strength of a transformer fluid is measured as its resistance to electrical stress. The method involves applying an AC current between two oil-immersed

electrodes. The gap between the electrodes is specified before the test. When the current arcs between the gap, the voltage recorded is the dielectric breakdown voltage. The property is sensitive to physical contaminants in the oil [14].

Dissolved gas analysis

DGA is a common tool in which one can predict the internal health of a transformer or more specifically, the condition of the insulating oil. During the aging process, the transformer oil generates decomposition gases from various loads and stresses. DGA has three main objectives: To check if the equipment is in good condition, to prevent failure by localising possible faults and monitor the operating conditions. Depending on the type of error, different types of gases are formed. The gases that are of interest are , , , , , and . In DGA, the change of the gaseous

concentration is of interest. It can be evaluated with the IEC method by looking at the ratios , , or by using Duval’s triangle where the types of fault are represented in a triangle with three percentages of relative concentration (% 4,% 2 2 and

% 2 4). Each zone in the triangle represents a type of fault [2] [16].

Oxidation stability

The oxidation stability refers to the resistance to oxidation by transformer oil without any change to its properties. Certain phenomena inside the transformer can be a cause to dissolved oxygen, temperature differences, moisture and other factors making the transformer oil more likely to undergo oxidation which may result in the production of peroxides and sludge products. The oxidation stability determines the quality of the transformer oil. [14] [17].

Aging

When in service, the transformer oil will be subjected to heat, electrical discharges and oxygen which may cause degradation. This is known as aging of the transformer oil. The aging processes involved depends on the operating conditions, the design of the electrical equipment and on the type of transformer oil [2]. The aging limits the oil from fulfilling its functions in terms of heat transferring and insulation since the aging products reduce both the electrical properties and cooling efficiency of the oil [18]. The aging is predominantly caused due to oxidation reactions when the mineral transformer oil is subjected to temperatures over 300 °C and electrical stresses form acids and sludge. The degradation also affects the solid insulation lowering its

dielectric strength [18]. The rate of aging is a function of temperature and moisture.

Moisture can be seen as the biggest problem in terms of the aging in transformers. Oil will age rapidly at high temperatures and moisture acts as a catalyst of the aging.

There are also other materials in a transformer that can act as catalysts; among them are copper, paint, and other metals [2]. There are several techniques for monitoring and assessing the oil and the solid insulation.

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16 During the oil’s lifetime, its condition is monitored to make sure that it fulfils its

functions. The oil condition tests for transformer oils can be divided into physical tests, electrical tests and chemical tests. In general, the monitoring of the colour, appearance, acidity, DDF and IFT will provide information about the oxidation of the oil. Oil can also be degraded by arcing [2]. Arcing is defined as the electrical discharge that is formed when current moves across a gap between two points and it causes formation of gases within the oil. This is usually monitored by DGA.

The aging process is different in synthetic esters and natural esters. It also affects the solid insulation differently.

Comparison of transformer oils

The performance of transformer oil is evaluated in how they handle ageing and under different types of stresses. As described earlier, aging of the transformer oil and the solid insulation is the largest issue in electrical insulation and that the aging affects almost all properties of both the solid insulation and the transformer oil. The ageing also affects the insulation in different ways depending on what type of transformer oil that is being used.

The moisture content in the oil-paper/pressboard insulation is affected differently whether it is a natural ester or a mineral oil. In a paper from Zhou et al. [19], the properties of pressboard under thermal aging was conducted and evaluated. The study compared mineral oil (Nytro Gemini X) and natural ester (Envirotemp FR3) and the tests were conducted at 130°C for 80 days and 100 °C for 220 days. The properties tested are moisture content in oil and pressboard, furfural content, viscosity, the AC breakdown voltage, acidity and dielectric loss of the oil.

Moisture content

Figure 2 and 3 - Moisture content in pressboard [19]

The moisture content in the mineral oil is several lower than the natural ester based oil but when observing the moisture content in percentage in pressboard, the

moisture content is higher in the mineral oil than in the natural ester. What is evident is that in mineral oil, moisture migrates from oil to pressboard during aging while the reverse phenomenon occurs in natural ester.

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17 Acidity

Figure 4 - Acidity content in pressboard [19]

There is no acidity increase for the mineral oil while in the natural ester, there is rapid increase in acidic products. This is caused by the hydrolysis in the natural ester because it releases fatty acids. The increased acidity appears to have no effect of the aging of pressboard.

Viscosity

The viscosity of ester oils is higher than mineral oil and even more so when exposed to thermal aging. This is to be expected because of the viscosity of natural esters are higher naturally.

Figure 5 - Viscosity in different oils [19]

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18 Furan content

Figure 6 - Furan content in pressboard [19]

The furfural generated by the decomposition of the pressboard can indirectly give information on the DP-value. From the figure, there is a large increase in furan compounds in the mineral oil in high temperatures within the first 50 days. This result, with the significantly lower moisture content in the pressboard, show that the solid insulation lasts longer in the natural ester oil than in the mineral oil.

Dielectric loss and breakdown voltage

The dielectric loss is significant in the natural ester. This is thought to be caused by the large number of polar groups in the natural ester while the mineral oil remains principally unchanged. In terms of the breakdown voltage, both types of oils

gradually decrease at the same rate but the breakdown voltage is higher in the natural ester.

Figure 7 and 8 - DDF and breakdown voltage of different oils [19]

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19 For the synthetic ester, it behaves almost exactly as the natural ester oil in the same conditions. In studies from Coulibaly et al. [16]and Gasser et.al. [20], the aging of pressboard and kraft paper were tested but under different conditions for both

studies. Both studies showed that in the ester oils, there is an increase of water on the oil but a decrease of water in the solid insulation, reducing the rate of aging. This is due to the hydrolysis reaction in the ester oils while in the mineral oil, the reverse phenomenon occurs, leading to a faster degradation of the cellulosic insulation.

Reuse of transformer oil

Reuse of transformer oil is of high importance for manufacturer of the oil but also for electrical utility companies. This is of economic interest because of the cost of buying new transformer oil and for environmental reasons. For aged mineral oil, there are three main techniques for recovering the oil: reclamation, reconditioning and re- refining.

Reclamation

Reclamation is a process that removes soluble and insoluble contaminants through a chemical or physical process. Reclamation of oil usually involves treatment with clay or other adsorbents. In reclamation, the aged oil is passed through a bed of active adsorbent material to remove degradation products. There are several types of

adsorbent material such as Fuller's earth, activated alumina or bauxite and molecular sieves. Fuller's Earth refers to natural adsorbent clays that have the properties to neutralise acids, adsorb polar compounds and decolourise into clear oil. The major advantage of oil reclamation is that it can be applied while the transformer is still in operation and the aging products are removed from the transformer. Typical Fuller's Earth reclamation systems use a mix of activated alumina and Fuller's earth [21]

[22].

Not all used oils are suitable for reclamation. Oils that contain PCB cannot be reclaimed because of the risk of contaminating other equipment.

Reconditioning

Reconditioning is the removal of contaminants and dissolved gases through

mechanical means. This is usually through filtering, vacuum degassing to remove the dissolved gases and other methods [21].

Re-refining

Re-refining is the use of refinery processes to re-refine used mineral oil into products that are suitable for reuse. While reconditioning and reclamation are in essence physical and molecular filtration techniques, re-refining restores the molecular structure of the used mineral oil, leading to principally new mineral transformer oil.

Typical processes involved are the same processes found at a refinery which include hydrotreatment, solvent extraction and others. It is also the only method where there is a possibility to treat mineral transformer oil containing PCB. PCB can be removed through the use of catalytic hydrotreatment. CSIRO developed the process using catalysts based on metal sulphides which are tolerant to most catalyst poisons. They were able to reduce the amount of PCB to less than 15 ng/m3 [23]. Hydrodec is a re- refining company utilizing the technology developed by CSIRO and is using it to refine all used mineral transformer oil to re-refined oil [24].

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Life Cycle Assessment

Definition of Life cycle assessment

It is known that in order to assess or to evaluate the environmental consequences of an activity or product, the impact from all parts of its life cycle, from raw material to eventual disposal, must be considered. This type of analysis is called a Life Cycle assessment. In LCA terms, it means that a product is followed from raw material acquisition ("cradle") to disposal ("grave"). Not all LCA’s are done by looking at every step. Some are done by something known as "cradle-to-gate" which leaves out the use phase and the waste management. There are other tools to evaluate environmental impacts such as EIA and ERA [23]. There is an international standard for LCA in terms of an ISO standard called ISO 14040 that lists the following application:

Identification of improvement possibilities, decision making, choice of environmental performance indicators and market claims [25]. These offer uniform assessment guidelines for how to perform an LCA.

An LCA study contains four main phases: goal and scope definition, inventory analysis, impact assessment and interpretation. In the goal and scope, the product and the purpose of the study is decided upon. The system boundaries, i.e. which processes to include in the study are also made during the goal and scope definition.

These in turn govern the system boundaries needed for the inventory analysis. An LCA relates environmental impact to a function of the product system which

necessitates a way to express the function in measurable terms, as a functional unit.

The functional unit is a measure of the function of the studied system and it provides a reference to which the inputs and outputs can be related. This enables comparison of two different systems that are part of the assessment. The inventory analysis is a description of the actual systems model according to the defined goal and scope. Only the environmentally relevant flows should be included in the model [25].

The LCI consists of construction of the flow model according to system boundaries, data collection for all the processes and transports in the product system and

calculation of the amount of resource use and emissions in relation to the functional unit. In the LCI, allocation is necessary to account for processes which have multiple outputs. The inventory analysis is then followed up by the LCIA. The purpose of the LCIA is to describe the information obtained in the inventory analysis into indicators showing the impact of the environmental loads and in a sense to rewrite the

information into more relevant environmental information and to aggregate the information from the LCI in fewer parameters. The final phase known as the Life Cycle interpretation aims to evaluate the impact assessment [25].

Most LCA can be categorized into two types, accounting LCA and change-oriented LCA. Accounting LCAs are focused on answering the question “What environmental impact can this product be responsible for” while change-oriented or consequential LCAs focus more on exploring how different alternative courses gives different outputs/consequences [25].

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21 System boundary and functional unit

The system boundaries for this LCA are set from the extraction and cultivation of the raw material to the production of the oils at the respective refinery. For the mineral oil, the system boundary differs for the two cases. In the first case, the system boundary will be, as for the vegetable oils, from extraction of raw material to the refinery and in the second case, the system boundary will be extended to include a disposal scenario in the form of re-refining the mineral oil. The functional unit is

“Production of one tonne of oil”.

Figure 10 - Diagram of cradle-to-grave model for mineral oil

Modelling with Simapro

Since there is no possibility of only using directly obtained data, primary data, we used the predefined datasets in Simapro. The databases used were Ecoinvent for the modelling of the mineral oil and Agri-footprint for the vegetable oils. Ecoinvent was developed by a Swiss organisation and is among the most developed databases for LCA studies covering over 10000 processes [26].

Figure 9 - Diagram of cradle-to-gate model

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22 Processes are divided between unit and system processes. Unit processes include upstream processes in the production of a product whereas system processes do not so. System processes compile the data and only gives the result of a product,

simplifying the data but giving no insight to the inputs or outputs [26].

In Ecoinvent, there is also a further distinction of the processes into market and transformation processes. Transformation processes contain all of the inputs for a product including the associated emissions and resource extractions but exclude transport inputs. Market processes also include the environmental impact of transportation from different regions and countries making a dataset contain the average transportation data for a specific product.

Agri-footprint is a database solely focused on agricultural products. It was developed by Blonk consultants and contains approximately 3500 products and processes. The database contains data on primary processes for example crops, feed compounds and background processes such as transportation and fertilizers. The database has three pre-defined allocation systems; mass, energy and economic allocation and for different locations in the world.

In this thesis, mass allocation is used for the vegetable oils and a mixture of transformation and market processes for the mineral oil.

To do the LCA, we used the software Simapro. Simapro is the leading software used in LCA studies and the Classroom Edition 8.2.0.0 was applied. In Simapro, the models of the mineral oil production process and the vegetable oil production processes were built in line with the previously defined system boundaries. Simapro distinguishes seven process types (materials, energy, transport, processing, use, waste scenario and waste treatment) each of which can be a unit process or a system process where a set of unit processes are described as one process. To form a product in Simapro, product stages are used. Product stages describe how a product is

produced, its usage and disposal. The product stage contains the flow data from the unit and system processes. Simapro has five product stages:

· Assembly: The assembly which defines the production stage of the product.

· Disposal scenario: The disposal scenario which describes the end-of-life scenario of the product.

· Disassembly scenario: The disassembly scenario which describes which parts of a product should be disassembled and where the disassembled parts will go.

· Reuse: The reuse stage which describes the process needed for reusing a product.

· Life cycle stage: The life cycle stage describes the total life cycle of the product.

Depending on the type of LCA study, it can include the assembly or more stages.

Each process in Simapro consists of three sections; documentation, input/output and system descriptions. The first section, documentation, contains information

regarding the particular dataset such as the name for the dataset and general

comments regarding the application of the dataset. The second section, input/output, contains all of the flows in and out of the processes. There are three types of inputs in Simapro: Inputs from nature, inputs from the technosphere in the form of materials

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23 and fuels and inputs from the technosphere in the form of electricity and heat. The outputs are divided into the categories emissions to air, emissions to water, emissions to soil and final waste flows. The third section, system description, contains detailed information and references of a process system. Once all of the data has been entered and is part of a life cycle of a product, the environmental impact of the product can then be evaluated with the selected impact assessment method.

To evaluate the environmental loads of different production methods and products in Simapro, an impact assessment method must be chosen. As defined in ISO 14040, any impact assessment method contains the elements classification and

characterization. They can also include the optional elements normalization and weighting [26]. The LCI contains information on the emissions, land use and other information caused by the life cycle of the products and the emissions and resources are assigned different impact categories. This step is called classification and it is important to point out that different emissions can be assigned to the same impact category and one emission can be assigned to several impact categories.

Elementary flow Climate change Ozone layer

depletion Eutrophication

1 kg x

100 gram x

1 gram CFC142b x x

5 gram x

Table 1 - Example of classification of emissions

Once the emissions have been separated into different categories, the emissions are multiplied with a characterisation factor to obtain the same unit. For example, 4 has a 25 times higher impact on global warming than 2 and therefore, 4 must be multiplied with a factor of 25 to obtain the unit 2- equivalents. This is known as the characterisation step [26].

Normalisation is used to see the environmental impact compared to a reference value and weighting is to show the relative importance of different impact categories. The information from the weighting can be used to produce a Single score which shows the total environmental impact for a product. The Single Score is used in comparative LCAs [26]

The impact assessment method chosen in this thesis is "ILCD 2011 Midpoint +”. The ILCD method is developed by the EC-JRC and the midpoint method offers the following 16 impact categories [27] [28]:

· Climate Change: The category Climate change measures the GWP of a product in kg CO2-equivalents. GWP is defined as a relative measure of how much heat a greenhouse gas traps in the atmosphere. All gases affect the environment but to a different degree and CO2 is set as the reference number 1 to which all other gases are compared.

· Ozone Depletion: The impact category for ozone layer depletion

accounts for the destruction of the stratospheric ozone layer over a time – horizon of 100 years. The unit is kg CFC-11 equivalents.

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24

· Human toxicity, cancer and non-cancer effects: the impact category for the human toxicity expresses the estimated increase in morbidity by cases per kilogramme of a chemical emitted. The model was developed by USEtox and for the cancer effects, the unit CTUh is used and for the non-cancer effects CTUe.

· Terrestrial eutrophication: The impact category for the terrestrial eutrophication accounts for the emissions of nitrogen dioxide and ammonia to the air. The unit is mole N-equivalents.

· Marine eutrophication: The impact category for the marine eutrophication accounts for the environmental fate of the emission of nitrogen containing nutrients. The unit is kg N to freshwater equivalents.

· Freshwater eutrophication: The impact category of freshwater eutrophication accounts for the environmental fate of the emission of phosphate containing nutrients. The unit is kg P to freshwater equivalents.

· Ionising radiation: The impact category of ionising radiation accounts for the level of exposure to radiation bodies. The unit is kBq 235 - equivalents.

· Photochemical ozone formation: the impact category for photochemical ozone formation is defined as the potential contribution to the formation of ozone from emissions of NO and it is expressed in the unit kg NMVOC – equivalents.

· Water resource depletion: The impact category for water resource depletion accounts for the abstraction of water from the ground and from rivers. The unit is m water equivalents.

· Acidification: The impact category of acidification accounts for the flows contributing to acidification such as ammonia, nitrogen oxide and sulphur dioxide. The unit is moles H+.

· Particulate matter formation: The impact category of particulate matter formation accounts for the formation of particulate matter such as 10,

2.5, and others. The unit is kg 2.5 equivalents.

· Freshwater ecotoxicity: The impact category for the freshwater ecotoxicity accounts for the emissions to freshwater based on the same model for the human toxicity. The unit is CTUe.

· Land use: The impact category for land use accounts for both land

occupation and land transformation. Land occupation is defined as the actual occupation of a square meter of land for one year and land transformation as the conversion of land from one use to another expressed in square meters of land converted. The unit is kg C deficit.

· Resource depletion- minerals and fossil: The impact category for the resource depletion accounts for the mineral and fossil depletion and it is expressed in kg Sb –equivalents per kg extraction.

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25 Choice of oils and assumptions for LCA

The oils that will be studied is the natural ester based oils and mineral oil. This is because there is a lack of data on the synthetic ester transformer oil. The additives required to make transformer oil are not included in the LCA and are assumed to be negligible. The vegetable oils that will be part of the LCA are rapeseed, soybean and sunflower oil. This is because of previous studies from BEES where LCA’s on different types of transformer oils have been made. BEES is a software developed by NIST where the environmental performance of building products are measured. It combines the LCA approach from the specified ISO 14040 and an economic performance evaluation to give an overall performance of a product [27]. The studies that are of interest are named after the products “ABB BIOTEMP” and “Cooper Environtemp FR3” and the study “Generic biobased transformer oil”.

In the models from the BEES software, carbon sequestration is included. Carbon sequestration is defined as the long-term storage and capture of carbon dioxide.

Capture can occur either through natural processes as photosynthesis or at the point where it is emitted [28]. In the case of vegetable oils, the carbon sequestration occurs during the cultivation of the crops and the amount of sequestration depends on the cultivation method [29]. The amount of carbon sequestration for the LCA will be based on the LCA prepared for the interest organisation United Soybean Board from Omni Tech International [30].

In the report, they stated that for one tonne of lubricant soy oil, 2955 kg of 2 is sequestered. Due to lack of data, the carbon sequestration for the rapeseed and

sunflower oil will be assumed to be 80% of that amount. The reason for this is that an estimate was required for the comparison of the oils and no studies were found that specifically studied the amount of carbon sequestration of rapeseed and sunflower.

The disposal scenario in the Simapro model will be divided into two cases, 80 % re- refining with 20% incineration and 75% re-refining with 25% incineration. As there was no information on the emissions emitted by incinerating one tonne of waste mineral oil, the pre-defined dataset “waste mineral oil” from Ecoinvent was used.

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26 Life cycle inventory

Mineral oil

The LCI data for the mineral oil was given to us from Nynas and accounts for the cradle-to-gate data for the production of one tonne of mineral base oil including the bulk transportation to Nynäshamn.

Soybean oil

Production of 1 tonne

of refined soybean oil Unit Cradle-to-gate Known inputs from

technosphere(materi als and fuels)

Crude soybean oil kg 1038

Water kg 540

Bleaching earth kg 5,4

Phosphoric acid kg 1,13

Sulfuric acid kg 2

Activated carbon kg 0,2

Sodium hydroxide kg 2,8

Known inputs from nature

Carbon dioxide, in air kg -2955

Emissions to water

Unsaponifiable matter kg 15

Oils, unspecified kg 18

Table 2 – LCI of soybean oil

The data for the soybean oil was taken from the Agri-footprint database in Simapro.

The carbon sequestration of the soybean oil has been added to the data as “Carbon dioxide, in air”. The crude soybean oil is derived from crushing of soybeans with the use of hexane as a solvent and is based on a soybean refining process in The

Netherlands. A small portion of the crude soybean oil is allocated for the soap stock that is formed as a by-product when refining the crude oil but its impact is considered to be negligible.

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27 Rapeseed oil

Production of 1 tonne of refined rapeseed oil

Unit Cradle-to-gate

Known inputs from technosphere

(materials and fuels)

Crude rapeseed oil kg 1032

Water kg 500

Bleaching earth kg 4

Phosphoric acid kg 0,791

Sulfuric acid kg 2

Nitrogen kg 0,5

Sodium hydroxide kg 3

(electricity and heat)

kg/t 6

Steam from natural

gas MJ 467,5

Electricity kWh 27

Known inputs from nature

Table 3 – LCI of mineral oil

The data for the rapeseed oil was taken from the Agri-footprint database in Simapro.

Just as for the soybean oil, a small portion of the crude rapeseed oil is allocated for the soap stock produced during refining. The crude rapeseed oil is derived through pressing and is based on a rapeseed oil refining process in Germany. The carbon sequestration has been added to the data.

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28 Sunflower oil

Production of 1 tonne of refined sunflower oil

Unit Cradle-to-gate

(materials and fuels)

Crude sunflower oil kg 1032

Bleaching earth kg 3,03

Energy from diesel MJ 342,45

Known inputs from technosphere (electricity and heat)

Steam from natural

gas MJ 731,5

Electricity kWh 54,8

Known inputs from nature

Table 4 – LCI of sunflower oil

The production data for one tonne of refined sunflower, just as in the two other oils, is taken from the Agri-Footprint database. The crude sunflower has been derived through physical refining (pressing) and the dataset is based on a sunflower refining process in Ukraine. The carbon sequestration has also been added.

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29 Re-refining

Re-refining of 1 tonne

of waste mineral oil Unit Known inputs

from technosphere (electricity and heat)

Electricity MJ 94

Process steam MJ 600

Process heat MJ 440

Energy from diesel MJ 342,45

Emissions to air

Carbon dioxide kg 36

Carbon monoxide kg 0,02

NOx kg 0,013

Sulfur dioxide kg 0,13

Particulates kg 0,004

Table 5 – LCI of re-refining

For the re-refining of the mineral transformer oil, the data is taken from a report commissioned by GEIR from IFEU institute where the re-refining of base oils was evaluated with an LCA [29] and the emissions data from the EC-JRC reference document for the refining of mineral oil and gas [7].The emissions from the hydrotreatment are based on a naphtha hydrotreater because of lack of data concerning the waste mineral oil.

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30

Case study

This case study has been divided in four sections. The first section is about scrappers, the second section is about legislation and licenses, the third about waste oil

management in Europe and the last section about the business model that is based on the previous sections.

Scrappers

Scrappers collect all types of waste including transformers. Not all scrappers can handle transformers because of the oil. Waste oil is classified as a hazardous waste and special certification is needed for its disposal. This means that there is

considerable amount of waste oil that can be gathered from these sites.

Legislation and licenses PCB

When it comes to the disposal of waste oils, there is legislation that must be considered. The EU has published the European waste oil directive which all

European countries must apply in their national legislation. The directive places duty on member states to ensure that the collection and disposal of waste oil do not harm citizens and the environment and that member states are required to give priority to regeneration of oils “where technical, economical and organisational structures so allow”. The waste oil that is not regenerated is to be burnt. That also includes used transformer oil that contains PCB but special regulations are in place for the disposal of PCB in each member state. A limit of 50 ppm is allowed for the content of PCB in regenerated transformer oil [30].

Transportation

Of interest for this case study is the legislation regarding transportation of waste across EU states. Shipments of waste entering or passing through EU countries must follow regulation 1013 from 2006 which stipulates the conditions of the transport of waste within the EU. The legislation encompasses all types of waste that in some way is removed from the site of use. The law applies for mainly four types of movement of waste: Waste shipped between EU countries, Waste imported into the EU form non- EU countries, Waste exported from the EU to non-EU countries and waste transiting through the EU. The law has annexes that contain the classification of waste into different waste types and codes. The waste codes consist of six digits and are called EWC-codes. Each type of waste has its own EWC-code [31].

For the shipment of hazardous waste such as waste mineral oil, prior written notification and consent is necessary. When the notifier intends to ship waste, a written notification must be submitted to the compentent authority in the country from which the waste is dispatched from. In the case of Sweden, for example, Naturvårdsverket is the competent authority.

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31 The starting point for the notification or application is firstly to identify the type of waste and find the correct EWC-code, specify to what country the waste should be sent to and how the waste should be handled. In the written application, a contract for the waste must be specified, a financial guarantee, overall process description of how the waste should be handled in the receiving country, description of how the waste will be transported, information from where it will be sent and on what country and company to which the waste should be sent [31].

To transport the used oil in vehicles, special certification is required. The license needed is called ADR licence and is issued by UNECE.

Excise duty

Excise duty must be paid for energy products in the EU. Energy product is an

umbrella term for different types of fuels such as natural gas, gas oil and mineral oil.

Each energy product is sorted into a tax category.

Any energy product is liable to tax when it is manufactured within the EU and when it is imported. Certain energy products such as mineral oil is covered by an excise duty suspension and be stored in a tax warehouse. This allows for manufacturing,

processing and storage of energy products without paying the excise duty. The excise duty is paid when it is no longer part of the excise duty suspension. This occurs when it leaves its tax warehouse, when it is destroyed or is received by a consignee. The excise tax will be then paid in the member state where this has occurred with its national tax rate [32].

The movement of excise goods is regulated by the EU directive No 684/2009 which states that the movement can only happen when a number of conditions is fulfilled.

The goods can only be moved between authorised actors and locations and an electronic administrative document must be submitted to EMCS which is a

computerised system for monitoring the excise goods that are under duty suspension.

Waste oil management

The Waste Framework Directive is the principal EU legislation concerning the reuse of waste oil. It essentially stipulates that member states should take the necessary steps to make sure that waste oils are collected separately and to encourage the best environmental outcome, prioritising the re-use of waste through recycling [34]. The directive does not state any specific way how to recycle the waste oil but allows each member state to apply measure leading to different ways of managing the waste oil.

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32 Poland

Poland has a closed loop system where only four recovery organisations are allowed to handle all waste oil on the Polish market. Oil producers which include

manufacturers, sellers and importers are required to keep records on the amount of oils they put on the market and report the data. The collective data is reported to the Ministry of Environment. One out of the four recovery organisations is a re-refiner.

In Poland, oil producers and importers have an obligation to handle the generated waste oil. This can be done individually or collectively through established

consortiums. There are currently six consortiums that take care of the entire management of the waste oil and are funded by their members.

A fee is paid by the producers and importers that is supposed to cover the cost of collection and treatment of the waste oil. Once the used oil has been regenerated, the producers sell them to the market as re-refined oil. PCB- contaminated oils are not treated in the same facility as other waste oils and subject to thermal treatment. Only two facilities in Poland can handle PCB-contaminated oil. [33] [34] [35].

Spain and Portugal

Spain has since 2006 created an integrated oil management system called SIGAUS that handle all waste oils in the country. This includes collection, transportation and regeneration of the waste oil. SIGAUS is a joint venture between the major oil

companies present in the Spanish market and more than 90 firms representing 90 % of the Spanish lubricant market are a part of the organisation which includes

transformer oil producers. To make this integrated system, SIGAUS has signed contracts and agreements with waste oil management companies which handle the following: collection, analysis, transportation, pre-treatment and regeneration.

Three companies handle the re-refining and regeneration of the waste oil and there are multiple companies that work with energy recovery in the form of incineration.

Figure 11 - Diagram of waste oil management in Poland [33]

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33 SIGAUS is financed through financial contributions of its members. The collection and management of waste oil in SIGAUS is free of charge.

The fee that is meant to cover the collection and management costs is passed from the producer onto the final consumer by placing the fee on the invoice in each step of the sales process. This is also meant to compensate waste oil managers for eventual operating deficits. Regarding PCB-contaminated oils, the collection of such oils is also free as long as they contain a PCB content that is less than 50 ppm. Oils that do not meet the specifications pay for the collection of the oil [33] [36].

Portugal operates in an almost identical system and their waste oil organisation is called SOGILUB. The fee in Portugal is higher than Spain. In Portugal, unlike Spain, all oil producers are required to have a contract with SOGILUB and it is financed from the levy and from the sale of waste oils. SOGILUB handles the collection, analysis, pre-treatment and disposal. Portugal also has two re-refiners that handle all of the oil recycling in the country [35] [38].

Figure 12 - Diagram of waste oil management in Spain [33]

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34 Germany

Germany has a free market system where all collectors and re-refiners compete for the available waste oil. Private end consumers dispose of their oil free of charge at their local lubricant dealer and industries pay a fee for the disposal of their waste oil.

In Germany, the waste oil companies have formed an organisation called BVA and it includes all of the re-refiners, regeneration companies in the country and many collectors that operate in the country. It is meant to support the waste oil industry in the country by means of information. There is no excise duty on lubricants in

Germany and the re-refining industry is highly subsidised when it comes opening new facilities and re-refined products.

There are many collectors present in the country and all of them must be authorised by each German state. There is only one re-refiner in Germany that specialises on used transformer oil but there are other companies that work with the reuse of used transformer oil [33] [37].

Figure 13 - Diagram of waste oil management in Portugal [33]

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35

Figure 14 - Diagram of waste oil management in Germany [33]

Belgium

Belgium is a country split into the regions Wallonia, Brussels and Flanders. Each region has its own waste oil legislation but all of them prioritise the reuse of waste oil after the EU directive either through regeneration, incineration or other means. In Belgium, producers or importers of oil have a take-back obligation where they have to take back used lubrication oil from private end users free of charge while industrial end users pay for their collection. All producers and importers must also have a waste control plan that is compliant with the regulations in the three regions. This can be done by each company or through an organisation called VALORLUB.

VALORLUB is a non-profit organisation and the only organisation recognised by the Belgian government that is allowed to handle the take-back obligation from the importers and producers. To finance this system, VALORLUB takes out several different fees.

There are currently a number of collectors and facilities where the waste oil is treated. VALORLUB signs contracts with these collectors and facilities and reimburse them for their services with the fees collected.. Two facilities are in Belgium but the rest in Netherlands, Germany and France [38].

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36

Figure 15 - Diagram of waste oil management in Belgium [38]

Finland

Finland has a state-run system where importers and producers of lubricants pay a tax on placed on the Finnish market to finance its oil collection. Priority is placed on the regeneration of waste oil according to Finnish law. The management of waste oil disposal lies at the Ministry of Environment and the company responsible for the collection of waste oil in the country is called Ekovoima Oy and is a part of Ekokem Group. The collection is done directly by Ekovoima in certain municipalities and in the rest of the country by companies that have a contract with Ekovoima. For

companies that have larger volumes and the waste oil is of sufficient quality in terms of the technical requirement, the collection is free of charge. For companies with smaller amounts, they pay for the collection.

The oil tax not only finances the waste oil collection but also the transport, storage and eventual pre-treatment of the waste oil. Ekovoima is funded by this tax and a state-granted subsidy as long as it is making a loss. No subsidy is granted to

Ekovoima when it generates profits and this is re- evaluated each year. Ekovoima is also financed by the sale of re-refined oils. They have three facilities for the treatment of waste oil, the Jämsänkovski plant that carries out the treatment of waste oil with high quantities of impurities, L&T Recoil plant which handles the re-refining of waste oils and Riihimäki plant which incinerates the oils that couldn’t be regenerated [33].

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37

Figure 16 - Diagram of waste oil management in Finland [33]

Greece

The waste oil management in Greece is handled by the Ministry of Environment and by the organisation ENDIALE. In Greece, importers and producers of lubricant oils must organise a system in which the used waste oil is recovered and processed either through regeneration or some other means. This responsibility can be fulfilled by each importer or producer individually or participate in an already approved management system, most commonly the one provided by ENDIALE. ENDIALE (formerly ELTEPE) has existed since 1998 and is a non-profit organisation that is approved from the Ministry of Environment to collect waste oil. ENDIALE has contracts with a significant number of collectors throughout the country and cover the majority of the Greek market.

The re- refining and regeneration companies buy the waste oil directly from

ENDIALE and in Greece, seven plants carry out this service including Cyclon Hellas which also re- refines used transformer oil. Regarding the financing of ENDIALE, the collection and processing costs are financed by the oil producers and by the sale of waste oil. The cost that is placed on the producers depends on the volumes of new oils placed on the Greek market [33] [39].

The Sustainability related opportunities and challenges with various transformer insulation fluids and business case on re-refining

The Sustainability related opportunities and challenges with various transformer insulation fluids and business case on

re-refining

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